You already know that eating ice cream too fast causes brain freeze, but there are plenty of other foods, like grapefruit, carrots and coffee, that can also cause some rather interesting after effects.

Grapefruit is often heralded as one of the healthiest foods to start your day with; it’s full of vitamin C and antioxidants, and has been proven to help lower cholesterol. For some, however, it may actually do more harm than good. If you’re on a prescription drug regimen, you may want to forgo the fruit altogether. That’s because grapefruit blocks enzymes in the small intestine that help to regulate drug absorption. If you consume grapefruit while on certain medications, you may end up digesting a larger dose. While that may not be a big deal for some prescriptions, it can be fatal for others. It is recommended that you talk to your doctor and find out if this super fruit is a super don’t.

Many people rely on coffee to get them going in the morning and stay alert throughout the afternoon, but just like Grandma always said, “You can have too much of a good thing,” especially if you’re also highly stressed. We all know that coffee can cause increased heart rate and insomnia in some people, but did you know that if you’re already under a great deal of stress, it can make you more likely to hear things that aren’t there as well? An Australian study had participants listen to white noise and pay attention for snippets of Bing Crosby’s White Christmas. People who drank five or more cups of coffee a day and reported being under the highest levels of stress were pretty sure they had heard the song. Problem was, the song was never played. Neuroscientist Simon Crowe, from Australia’s La Trobe University, led the study and said that caffeine, when consumed at high levels and combined with high stress, can make people "more likely to 'overreact' to the environment – i.e., to hear things that just aren't there."

A 2006 study held at Charles University in Prague examined the impact of red meat consumption on “body odor attractiveness.” Researchers looked at two control groups of men – those who ate red meat and those who didn’t. After a two-week diet, samples of the scents emitted from their bodies were collected and presented to 30 women. Overwhelmingly, the women preferred the smell of the non-meat eaters.

According to a study published by the journal Evolution & Human Behavior, there is a direct correlation between one’s levels of carotenoids and one’s perceived attractiveness. Scientifically speaking, it has to do with color pigments. Certain foods such as plums, apricots, kale, spinach, sweet potatoes and carrots, contain pigments called carotenoids that will give your skin a yellow tint. The UK study showed that the warm “glow” obtained after just two months of generous carotenoid consumption made subjects seem more attractive and healthy to study participants.

Always consult with your healthcare provider before consuming something that you think might have a strange reaction with your body or current medication. While some foods may cause unfavorable effects, there are plenty that can help you feel and look your best – so find out what works for you.